The invention relates to a working method for cleaning a swimming pool using a cleaning device that moves backwards and forwards across the floor of a swimming pool and has a drive mechanism that can be switched to forward or backward travel and is actively connected to drive wheels or drive tracks, a respective motor for each of a left-hand-side and a right-hand side part of the drive mechanism, a control apparatus for controlling the drive mechanism, and contacts arranged at the front and rear to generate control signals in the event that the cleaning device approaches a swimming pool wall or an obstacle. The invention further relates to cleaning device for cleaning a swimming pool for carrying out the method according to the invention.
Cleaning devices moving automatically backwards and forwards on the bottom of the swimming pool have been known for a considerable time. In most cases, however, they have the disadvantage that pools of irregular shapes cannot be cleaned automatically and reliably. Particularly in the low-cost range, there is a need for appropriate simple devices.
DE-3 110 203 describes a method and a device for cleaning a swimming pool which, in a known manner, moves backwards and forwards on the bottom of a water-filled swimming pool and, in doing so, cleans it by suction. The device has two motors, so that the two sides of the drive mechanism can run forwards or backwards or remain stationary independently of each other. The device additionally possesses a control apparatus which is influenced by four sensors arranged at the corners of the device and controls the travel of the device on the bottom of the swimming pool between opposite swimming pool walls in a zigzag path. The device travels alternately forwards and backwards. It does not turn at the swimming pool walls, but performs small pivoting movements there on each occasion. These pivoting movements firstly enable the cleaning device to be aligned relative to the swimming pool wall and secondly allow a new direction of movement to be set subsequently. Since the cleaning device has one motor for each of the two sides of the drive mechanism, one of the two motors is shut down on each occasion in order to achieve the alignment movements and changes of direction, the other motor continuing to run during the alignment operation or during a delay period. As a result, the cleaning device rotates about the shut-down drive part.
One of the disadvantages of this cleaning device resides in the fact that changes of direction can only be performed relatively imprecisely. The achievable accuracy of the angle of change of direction depends on factors which are difficult to control, such as, for example, the different dynamic performance of the two sides of the drive (inter alia, during starting conditions) and the pronounced dependence on the delay period. The consequence of this is that, especially in the case of relatively long travels, the reliable overlap of the cleaning tracks and hence the complete cleaning of the pool bottom may not be guaranteed under certain circumstances. The principle disadvantage, however, resides in the fact that this cleaning device is not suitable for pools of different sizes without careful adjustment of the delay period and is only suitable for rectangular or square pool shapes.
The object of the present invention is therefore to provide a simple method for cleaning and a reasonably priced cleaning device which can be used both in pools of different sizes and in pools of different shapes and guarantee reliable cleaning of the pool bottom.